Most human capacities decline in old age. An apparent exception is "verbal IQ" as measured by subtests of standard intelligence tests. Because verbal skills show no obvious decline, little research attention has been focused on aging and changes in verbal abilities. This may be a mistake. Various language capacities are important in reasoning, problem-solving, and thinking tasks. Performance on such tasks clearly does deteriorate with age; the decline may result from changes in psycholinguistic capacities which are important, but not detected by standard IQ measures. The proposed research uses a variety of refined measures to determine if age-related changes occur in conceptual organization underlying vocabulary and if so, the nature of the changes. This proposal views human memory as an organized network of nodes corresponding to concepts. Each concept-node has multiple links to other concepts in the system. These links provide the system with its ability to abstract, generalize, analogize and reason, among other things. The first 3 experimental series represent different ways to determine if some conceptual links are lost in old age and if so, what kinds of links are most likely to be lost. Series 1 and 2 concern links with other concepts, while Series 3 concerns links between a concept and the vocabulary item by which it is represented. Links may appear to be lost because of access failure rather than loss per se. Experimental Series 4 addresses the possibility that aging involves more frequent and persistent failures of access to stored information. It is also possible that aging involves slower access to information. Series 5 is designed to discover if access is slower to vocabulary items themselves; Series 6 considers slowed access to abstract conceptual information underlying vocabulary items. The studies constitute basic research in an applied area. The outcomes will add to the data base of life-span psychology. This type of work is a necessary adjunct to improvements in physical health care, and provides the type of data which must inform potential remedial programs directed at the problems of old age.